Carbamate- or urea-functional compositions have been described for uses such as curable compositions, particularly curable coating compositions. They are often used for topcoats in the automotive and industrial coatings industry. Color-plus-clear composite coatings are particularly useful as topcoats where exceptional gloss, depth of color, distinctness of image, or special metallic effects are desired. The automotive industry has made extensive use of these coatings for automotive body panels. Color-plus-clear composite coatings, however, require an extremely high degree of clarity in the clearcoat to achieve the desired visual effect. High-gloss coatings also require a low degree of visual aberations at the surface of the coating in order to achieve the desired visual effect such as high distinctness of image (DOI).
Such coatings are especially susceptible to a phenomenon known as environmental etch. Environmental etch manifests itself as spots or marks on or in the finish of the coating that often cannot be rubbed out.
Curable coating compositions based on curable components having carbamate or urea functionality have been proposed have been described in the art to provide etch-resistant coatings, e.g., U.S. Pat. No. 5,356,669 and WO 94/10211.
In addition to resistance to environmental etch, a number of other characteristics can be desireable. For example, it may be desireable to provide a coating having a high degree of flexibility. This can be particularly advantageous if the substrate on which the coating is placed is itself flexible, as in the case of plastic, leather, or textile substrates.
It is also desirable to reduce the amount of solvent required in coating compositions in order to reduce the volatile organic content (VOC), which is better for the environment.
Finally, it is desirable to provide options of different types of carbamate- or urea-functional materials to provide coatings with a good combination of properties such as durability, hardness, and resistance to scratching, marring, solvents, and acids.